I don't really agree with the concept of "deserving" - if you win it you deserve it, if you don't win, you don't. But allowing for the idea that someone SHOULD win a slam, then Murray paid his dues and got there in the end.

Comparing Potro to Murray.
Murray won his slam in his fifth final. He had won many other big tournaments with an Olympic gold and 8 masters title. Potro has nothing other than his slam, no other finals, master titles etc.